The present invention relates to partial discharge sensing systems. More particularly, the present invention relates to an online partial discharge sensing system that includes a partial discharge sensor and an access port.
Partial discharge sensing can be used to assess the condition of power cables. More particularly, partial discharge sensing can be used to detect deterioration of insulation of power cables by detecting high frequency currents that are created by small gaps, voids or other deterioration in power cable insulation. Online partial discharge sensing refers to frequency domain testing conducted on objects that remain energized during testing.
Typically, a partial discharge sensing system includes a partial discharge sensor, a spectrum analyzer, and a signal cable for carrying electrical signals between the sensor and the spectrum analyzer. In order to conduct a partial discharge test, an operator positions the sensor at a test location on a power cable. Known systems utilize split core sensors, which require the operator to clamp the split core sensor around the power cable. Next, the operator manually conducts a partial discharge test using the spectrum analyzer.
In order to conduct testing on power cables that are located within enclosures, an operator must open the enclosure and position a partial discharge sensor on a power cable located inside. This requires that the operator be in close proximity to power cables and other components within the enclosure. This can present a safety hazard to operators, who risk electrical shock, electrocution, and other serious injury from equipment housed within such enclosures.